[the_duke]

The biggest challenge is providing all the functionality that users want with a clean UI.

There's a trap and tradeoff in making an interface too clean: discoverabilty suffers.

Some users might never go beyond the simplest of use cases, but more advanced things need to go beyond that and it shouldn't be hard to find out how.

If users have to google how to do something, you have lost.

Apple is a good example of this. They value their clean and intuitive interfaces.

But I don't think they actually are. Give an iPhone to someone who hasn't used it in a while and see how well they handle things...

[weego]

This touches on a problem our current product has. We're on the second iteration where the first iteration had almost no traction yet the design and features coming from the product side assume so much implicit knowledge of the business that there's no way a complete newbie can look at it and feel confident that they know what is going on.

Because we have no traction and thus no metrics we're in a vicious "I think it should work like this so let's do it that way because you can't prove people won't like it" cycle.

[cjcenizal]

Sounds like you should check out "Don't make me think" by Steve Krug! It's a quick read and contains very simple effective advice on how to make your UI usable. He outlines ways to do very cheap user testing to add objectivity to the decisions you're describing.